Modeling diffusional coarsening in eutectic tin/lead solders: a quantitative approach

This paper presents a quantitative simulation of the phase separation and c oarsening phenomenon in eutectic tin/lead (SnPb) solders. The computer mode ling is based on continuum theory and phase field models that were evaluate d using the most recently available data for the free energy of the tin/lea d system, diffusional and mobility coefficients, elastic constants as well as surface tensions of both phases. The model presented allows us to study the influence as well as the interaction between classical diffusion of the Fickean type, surface energies according to Cahn and Hilliard, as well as stresses and strains on phase separation and coarsening. An attempt is made to compare the temporal development of a eutectic SnPb microstructure at d ifferent temperature levels and subjected to different stress levels as pre dicted by the model to actual experiments. (C) 2001 Elsevier Science Ltd. A ll rights reserved.